Since people with anorexia nervosa exhibit extreme weight dysregulation, we decided to study this relationship further.”

The study compared fecal samples of women with anorexia before and after treatment.

Before treatment the women had gut bacteria with much lower diversity.

Low diversity is a sign of poor health.

After treatment, with their weight restored, bacterial diversity had increased, but it was still not as high as healthy individuals.

Dr Carroll said:

“We’re not saying that altering gut bacteria will be the magic bullet for people with anorexia nervosa.

Other important factors are at play, obviously.

But the gut microbiota is clearly important for a variety of health and brain-related issues in humans.

And it could be important for people with anorexia nervosa.”

Nevertheless, this could offer hope for a new type of treatment, said Dr Cynthia Bulik, another study author:

“Currently available treatments for anorexia nervosa are suboptimal.

In addition, the process of weight gain and renourishment can be extremely uncomfortable for patients.

Often, patients are discharged from the hospital, and within months and sometimes weeks they find themselves losing weight again and facing readmission.

If specific alterations in their microbiota could make renourishment less uncomfortable, help patients regulate their weight, and positively affect behavior, then we might see fewer readmissions and more cures.”